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HARRY HOPKINS/MONTREAL
FIREFIGHTING IS A matter of timing — getting sufficient water to the right place (even remote places) early, and keeping it coming. The perfect delivery
machine for that task is an aircraft, which can
link water supply and fire directly and rapidly.
Over the years, numerous aircraft have been
adapted to a firefighting role, but
Bombardier's twin-turboprop Canadair CL-
415 is unique as a new-build amphibian pri
marily dedicated to the task.
Flight International evaluated the CL-415 as
a follow-on from the test, made 30 months
ago, of the CL-215T turboprop modification
of the original CL-215 piston-engined water-
bomber.
By no stretch of the imagination could the
CL-215 be described as a thing of beauty, and
its development into the CL-415 has done lit
tle to change that. The airframe is festooned
with airflow fences and vortex generators, to
optimise the low-speed aerodynamics of the
wing and empennage, which live in an asym
metric propwash from the two large propellers
which have the same direction of rotation.
A huge fin and rudder are supplemented by
"finlets" to each side of the tailplane, which
are angled 5° from the fore/aft line. Deep baf
fles below the wing protect the outer sides of
the engine intakes.
The only clear external difference between
the CL-215T and the CL-415 is that there are
four drop doors instead of two. The release
setting of their pre-loaded door actuators has
been increased to resist a flight vertical load of
2.2G, to cure a slight weeping found during
manoeuvring during flight tests.
Those doors serve a drop system which has
been increased in capacity and flexibility. The
upper parts of the water tanks are reshaped to
bulge forward — adding 15% volume, for a
total of 6,1401itres. The overfill/air relief ducts
are larger than before, and float-type contents
sensors settle more quickly to a reading' than
potentially more accurate pressure-sensing.
A flatter foam tank, holding 6001itres, is
now located under the starboard four-seater
bench (up to 14 firefighters can be carried),
and holds concentrate for 19 drops. The
Quebec Government's aircraft have two foam
tanks. Protective coatings and paints have
been further improved.
The optional auxiliary power unit (APU) is
30 FLIGHT INTERNATIONAL 11 - 17 October 1995